By Kevin Bundy and Mary Booth The science is clear: To head off climate change’s worst effects, we must rapidly shift from fossil fuels to clean, efficient, low-carbon alternatives.

But not all alternative energy sources are created equal. Generating electricity by burning wood and other “biomass” could actually make our climate problems worse. President Barack Obama’s new Clean Power Plan, released on August 3, acknowledges the potential for a biomass pollution problem.

Unfortunately, some members of Congress think they can legislate away the scientific facts altogether. Senate and House appropriators have advanced bill language that would force the EPA to ignore carbon pollution from burning trees, regardless of what the science says.

That’s a bit like trying to prevent plane crashes by abolishing the law of gravity. It looks downright silly, and it won’t work. The climate obeys the laws of physics, not the whims of Congress.

Biomass power plants emit three to four times as much climate-warming carbon dioxide at the smokestack as natural gas power plants and one-and-a-half times as much as coal plants, per megawatt of electricity produced. That means replacing fossil fuels with biomass will increase, rather than decrease, power sector smokestack emissions.

Some claim this pollution can be ignored based on the theory that it will be offset by new tree growth, or that burning "waste" wood for energy emits no more carbon dioxide than letting those materials decompose.

The science shows it takes from decades to more than a century for forest growth or avoided decomposition to offset the immediate emissions from burning wood for energy. We don’t have that kind of time: Our climate is sliding into chaos now.

Ignoring biomass carbon pollution threatens forests, too. In Europe, where they don’t count the carbon from biomass, massive power plants burn processed wood pellets imported from all over the world, including the U.S. And despite industry claims, those pellets aren’t made only of so-called “waste.” Corporations have been caught clearcutting mature hardwood forests in the Southeast to make pellets for British burners.

Burning wood is also just plain dirty. Most biomass boilers emit pollutants that aggravate asthma and other respiratory diseases at about the same levels as coal plants. Plants that burn contaminated fuels, like pressure-treated lumber and old railroad ties, can have significant emissions of air toxics. Like other incinerators, biomass plants are often built in low-income and minority communities already overburdened with pollution. Compared to truly clean energy from the wind and sun, biomass will always be the dirtiest “renewable” option.

The biomass industry, however, has powerful friends on Capitol Hill who are determined to ignore those troubling truths. The House even approved an appropriations rider from Maine Rep. Bruce Poliquin that would hamstring the EPA’s ability to enforce regulations that limit the amount of lead, mercury and dioxins that biomass plants emit.

The Obama administration has rightly opposed Congress’s anti-science effort to ignore biomass carbon pollution. Nonetheless, the EPA still intends to let states count biomass power as a “renewable” option in complying with the Clean Power Plan.

Generating more electricity with wood can only undermine the president’s efforts on climate. The Clean Power Plan clearly requires reductions in carbon pollution. But building more biomass power plants will increase carbon pollution – most likely for many decades beyond the Clean Power Plan’s 15-year timeline.

The EPA, perhaps looking for a political compromise, suggested in the final Clean Power Plan that it might treat wood from “sustainably managed” forests as safe for the climate. Forest sustainability standards, however, typically don’t count carbon emissions. And even if a forest is currently growing, accelerated logging for biomass fuel still increases atmospheric carbon dioxide – a bad deal for both forests and the climate.

At least the Clean Power Plan recognizes the basic scientific fact that burning trees for energy might affect the climate. Now Congress needs to drop the silly idea that it can pass laws telling the atmosphere how to behave.

We need to get off fossil fuels, including natural gas, as fast as we can. But the biomass cure – which threatens not only the climate, but also the nation’s forests and the health of our communities – could be worse than the disease.

Kevin Bundy is the Center for Biological Diversity’s climate legal director. Mary Booth, Ph.D., is the director of the Partnership for Policy Integrity.